// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_SOCKET_SOCKET_H_
#define NET_SOCKET_SOCKET_H_

#include <stdint.h>

#include "net/base/completion_callback.h"
#include "net/base/net_export.h"

namespace net {

class IOBuffer;

// Represents a read/write socket.
class NET_EXPORT Socket {
public:
    virtual ~Socket() { }

    // Reads data, up to |buf_len| bytes, from the socket.  The number of bytes
    // read is returned, or an error is returned upon failure.
    // ERR_SOCKET_NOT_CONNECTED should be returned if the socket is not currently
    // connected.  Zero is returned once to indicate end-of-file; the return value
    // of subsequent calls is undefined, and may be OS dependent.  ERR_IO_PENDING
    // is returned if the operation could not be completed synchronously, in which
    // case the result will be passed to the callback when available. If the
    // operation is not completed immediately, the socket acquires a reference to
    // the provided buffer until the callback is invoked or the socket is
    // closed.  If the socket is Disconnected before the read completes, the
    // callback will not be invoked.
    virtual int Read(IOBuffer* buf, int buf_len,
        const CompletionCallback& callback)
        = 0;

    // Writes data, up to |buf_len| bytes, to the socket.  Note: data may be
    // written partially.  The number of bytes written is returned, or an error
    // is returned upon failure.  ERR_SOCKET_NOT_CONNECTED should be returned if
    // the socket is not currently connected.  The return value when the
    // connection is closed is undefined, and may be OS dependent.  ERR_IO_PENDING
    // is returned if the operation could not be completed synchronously, in which
    // case the result will be passed to the callback when available.  If the
    // operation is not completed immediately, the socket acquires a reference to
    // the provided buffer until the callback is invoked or the socket is
    // closed.  Implementations of this method should not modify the contents
    // of the actual buffer that is written to the socket.  If the socket is
    // Disconnected before the write completes, the callback will not be invoked.
    virtual int Write(IOBuffer* buf, int buf_len,
        const CompletionCallback& callback)
        = 0;

    // Set the receive buffer size (in bytes) for the socket.
    // Note: changing this value can affect the TCP window size on some platforms.
    // Returns a net error code.
    virtual int SetReceiveBufferSize(int32_t size) = 0;

    // Set the send buffer size (in bytes) for the socket.
    // Note: changing this value can affect the TCP window size on some platforms.
    // Returns a net error code.
    virtual int SetSendBufferSize(int32_t size) = 0;
};

} // namespace net

#endif // NET_SOCKET_SOCKET_H_
